The present invention relates to an integral servomechanism and, more particularly, to an improved servomechanism combining a torque motor, synchro receiver, isolation transformer and electronics within a single housing.
The use of synchro-torque systems is well known in the prior art. One application of such a system is for data transmission from a remote location within an aircraft to the cockpit. In this type of system, a synchro transmitter is utilized to provide an electrical indication of an aircraft function, such as the position of a flap to which the synchro transmitter is mechanically coupled. The transmitter generated signal is then applied over connecting electrical wiring to a synchro receiver. The signal drives the rotor of the receiver to a new mechanical position which generates its own signal to balance the received transmitter signal. Such an arrangement is disclosed in my U.S. Pat. No. 3,641,532 that issued on Feb. 8, 1972 entitled "Fault Monitor For Use Within a Synchro-Torque System," which is assigned to the same assignee as the present invention.
When the synchro receiver is to be used for an application which requires additional torque, it is not uncommon in the prior art to combine the synchro receiver with a torque motor. Such an application is shown in U.S. Pat. No. 3,530,345 by F. K. Ibrahim et al., which issued Sept. 22, 1970. This device is intended to replace the synchro receiver within a synchro-torque system with an interchangeable unit that produces greater output torque.
Because the unit shown within the Ibrahim et al. patent is intended as a direct replacement for a synchro receiver, it, by necessity, operates at the same input voltage and frequency as the receiver it replaces, i.e., 90 volts, 60 cycle or 90 volts, 400 cycle. Due to the requirement for a high input voltage, it is not possible to use present-day integrated circuits which operate at voltages lower than the 90 volts in the Ibrahim et al. servomechanism. The solution to this problem is to utilize a transformer or other voltage step-down device between the power supply used in the synchro-torque system and the replacement for a synchro receiver. If this were done, however, the integral servomechanism would not be an interchangeable item. The Ibrahim integral servomechanism is also constructed from non-standard parts and is difficult to repair.